ok guys heres the deal. i've got a 350 with 9:1 compresson and a mild cam one step up over stock. i am running a aluminum holley contender dual plane intake. my heads are set of 305 smogger heads out of the 80's i think they have 1.94 intake and 1.54 exhaust and a small fuel runner. i also have a set of 4 to 1 headders. I was wondering what size jets should i use for this configureation? i am currently rebuilding this animal so any help would be great.

Thanks
Matt

 

Start with what's in there.

After you get the engine running, rejet as required to tune it properly.

 

thanks but i got this carb used and it never was on the iroc. the guy i bought it off of said that it was on a 400hp drag car. i do not have this and i was wondering what a good base would be to start out.
Thanks for any help
Matt

 

A "good" starting point would be clsoe to what Holley sends in box. 6.5" power valves and 76 squared jets.

 

It wouldn't have squared jets unless it had a secondary power valve or no power valve (primary or secondary).

The vast majority of 750 DP's, like your basic 4779-1 and up, would have something more like 71/80 jets ( http://www.holley.com/HiOctn/ProdLine/CarbList.pdf ).

 

Good point, tunnel vision- go fast thinking got me again

 

I have a mild 350 with a 670cfm street avenger carb...and right now i have the 64/66 jets in mine.

 

I have a 750 double pumper. Mine came w/ a 6.5 power valve in the front, and plugged in the rear. It came jetted with 71/80. I think this would be a bit rich for you though. I'd jet down a couple sizes and go from there, reading the plugs.

 

Thanks for all the help guys, I will post up my results.

Matt

 

i would try to get another carb , possibly a 650 dp. i dont know if this is in your budget. a 750 dp i much too big for your motor.you can add more fuel but the cfm will not change and 750cfm i just too big.i hope it works out for you though.

 

what is squared jets ?

 

same size jets front and rear metering blocks

 

whats the long thing the jets go in the sec side?

 

jet extensions, they make sure jets stayed submerged in fuel when leaving hard since the fuel in the bowl will naturally be pushed rearward and up the back of the bowl so jets can/could be sucking air instead of fuel...